Concentrating solar power (CSP) technology is one of the promising options to generate green energy. However, the cost of kWhe produced is relatively high compared with fossil resources and can be reduced by integrating a cogeneration system exploiting waste energy. In this study, a technico-economic evaluation of a 1 MWe CSP plant with a condensation heat (85 °C) is investigated. The temperature constraint is set to meet the thermal separation needs of the draw solution of a forward osmosis desalination process. The purpose of this study focuses on the factors involved in reducing the cost per kWhe, which are the selection of the organic fluid used in the organic Rankine cycle and the appropriate choice of the solar multiple (SM) according to the appropriate storage hours (SH) maximizing the CSP thermal efficiency. The performance of different organic fluids was compared, based on the calculation of the thermodynamic cycle efficiency. The cyclopentane was retained for its reduced cost. Operating with this fluid, a sensitivity analysis was realized to test the effect of the solar multiple and storage hours on the power plant. It allows us to conclude that different appropriate combination between storage hours and solar multiple can be chosen, for the needs of our project, we opt for 8 h and 1.85, respectively. Thus, in this case, the cost of kWh was found to be 23.95¢.